IGF::OT::IGF NRA AWARD. SEA-SURFACE TEMPERATURE (SST) IS A KEY VARIABLE IN DEPICTING CLIMATE CHANGE, AND TH…

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IGF::OT::IGF NRA AWARD. SEA-SURFACE TEMPERATURE (SST) IS A KEY VARIABLE IN DEPICTING CLIMATE CHANGE, AND THE COMMITTEE ON EARTH OBSERVATION SATELLITES AND THE WORLD CLIMATE RESEARCH PROGRAM HAVE DESIGNATED SST AS AN ESSENTIAL CLIMATE VARIABLE. THERE CURRENTLY EXISTS A 33-YEAR CLIMATE RECORD OF SST INFERRED FROM SATELLITE INFRARED (IR) RADIOMETERS. THE SUOMI NPP VISIBLE INFRARED IMAGER RADIOMETER SUITE (VIIRS) CONTINUES THIS TIMESERIES OF IR SST RETRIEVALS. THE THERMAL IR RADIATION SEEN BY SATELLITE RADIOMETERS IS A PRODUCT OF BOTH THE OCEAN'S SKIN TEMPERATURE AND THE TEMPERATURE OF THE INTERVENING ATMOSPHERE. WATER VAPOR, AEROSOLS, AND CLOUDS ALL CONTRIBUTE TO THE ATMOSPHERIC PART OF THE TEMPERATURE MEASUREMENT. IT IS NOT UNCOMMON FOR 80% OF THE RECEIVED RADIATION TO COME FROM WATER VAPOR. COLD AEROSOLS IN THE UPPER ATMOSPHERE CAN SIGNIFICANTLY DEPRESS TEMPERATURE SEEN BY THE SATELLITE, AND UNDETECTED CLOUDS, WHICH ARE COMPLETELY OPAQUE IN THE THERMAL INFRARED, WILL PRODUCE A CLOUD TOP TEMPERATURE MEASUREMENT RATHER THAN A MEASUREMENT OF SST. SST RETRIEVAL ALGORITHMS ARE DESIGNED TO REMOVE THE ATMOSPHERIC PART OF THE MEASUREMENT BY USING THE SPECTRAL INFORMATION IN THE THERMAL IR MEASUREMENTS ALONG WITH CLOUD CLEARING ALGORITHMS. HOWEVER, SOME OF THE ATMOSPHERIC TEMPERATURE SIGNAL UNDOUBTEDLY LEAKS THROUGH THE RETRIEVAL ALGORITHM, AND THE REPORTED SST IS A COMBINATION OF THE TRUE SST AND A TEMPERATURE ASSOCIATED WITH THE ATMOSPHERE. WE CALL THIS ALGORITHM DEFICIENCY `ATMOSPHERIC CROSSTALK , AND IT IS BY FAR THE LARGEST SOURCE OF ERROR FOR IR SST RETRIEVALS. ATMOSPHERIC CROSSTALK IS A VERY SERIOUS CONCERN FOR CLIMATE RESEARCH. POSSIBLY THE MOST IMPORTANT ASPECT OF CLIMATE VARIABILITY, EITHER ANTHROPOGENIC OR NATURAL, IS THE COMPLEX INTERACTION BETWEEN THE OCEANS AND THE ATMOSPHERE. ONE EXAMPLE IS THE PACIFIC DECADAL OSCILLATION. IT IS ESSENTIAL FOR SATELLITE CLIMATE MEASUREMENTS TO UNIQUELY DISTINGUISH SEA SURFACE TEMPERATURE VARIABILITY FROM ATMOSPHERIC TEMPERATURE VARIABILITY. ATMOSPHERIC CROSSTALK IS A WELL-KNOWN PHENOMENON AND HAS BEEN DISCUSSED IN THE LITERATURE. OUR INVESTIGATION WILL BUILD ON THE PAST RESEARCH AND PROVIDE A MUCH MORE COMPREHENSIVE AND QUANTITATIVE ANALYSIS OF ATMOSPHERIC CROSSTALK, PARTICULARLY AS IT RELATES TO SENSING CLIMATE VARIABILITY. THE INVESTIGATION WILL BE BASED ON THE SENSOR COMBINATION OF THE S-NPP VIIRS AND THE JAPANESE SPACE AGENCY MICROWAVE (MW) RADIOMETER AMSR2. THE AMSR2 MW SST RETRIEVALS ARE NOT AFFECTED BY THE ATMOSPHERE (EXCEPT FOR RAIN WHICH IS EASILY EXCLUDED). ALSO AMSR2 PROVIDES ACCURATE RETRIEVALS OF WATER VAPOR V AND LIQUID CLOUD WATER L. HENCE AMSR2 PROVIDES AN IDEA L REFERENCE FOR STUDYING THE ATMOSPHERIC CROSSTALK IN THE VIIRS RETRIEVALS. USING THE INFORMATION WE OBTAINED FROM THE ATMOSPHERIC CROSSTALK ANALYSIS, WE WILL DEVELOP AND IMPLEMENT NEW, PHYSICALLY BASED SST RETRIEVAL ALGORITHMS FOR VIIRS. TWO ALGORITHMS ARE PROPOSED: VIIRS STANDALONE AND COMBINED VIIRS AND AMSR2. THE VIIRS STANDALONE ALGORITHM IS A PHYSICALLY PARAMETERIZED STATISTICAL ALGORITHM (PPSA). THE PPSA+AMSR2 ALGORITHM IS AN EXTENSION OF THE PPSA THAT REQUIRES THE AMSR2 RETRIEVALS OF SST, V, AND L. BOTH ALGORITHMS WILL BE DESIGNED TO MITIGATE THE ATMOSPHERIC CROSSTALK ON SPATIAL AND TEMPORAL TIMESCALES ASSOCIATED WITH CLIMATE CHANGE. THE ANALYSES AND ALGORITHMS DEVELOPED UNDER THIS VIIRS/AMSR2 INVESTIGATION WILL BE DIRECTLY APPLICABLE TO THE MODIS/AMSR-E SENSOR COMBINATION ON THE NASA AQUA SPACECRAFT. AS AN ADDITIONAL-COST OPTION, WE PROPOSE TO INCLUDE MODIS/AMSR-E AS PART OF THE INVESTIGATION.